From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 988C4C433EF for ; Tue, 17 May 2022 13:31:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347813AbiEQNbf (ORCPT ); Tue, 17 May 2022 09:31:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347847AbiEQNay (ORCPT ); Tue, 17 May 2022 09:30:54 -0400 Received: from relay10.mail.gandi.net (relay10.mail.gandi.net [IPv6:2001:4b98:dc4:8::230]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F2E0DFD0; Tue, 17 May 2022 06:30:50 -0700 (PDT) Received: (Authenticated sender: miquel.raynal@bootlin.com) by mail.gandi.net (Postfix) with ESMTPSA id 56CC8240012; Tue, 17 May 2022 13:30:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1652794249; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=PMfOpTgcEbu3EpZVSKfpa5HDynTgAT8/eYq8vW0Qg0w=; b=Kksfx9sL7zOWrnb2cgknIEscypRaYPv7+qWkollCVn8QqxIgIizjUswXGjYGzZHJmiaabL 7jcJksId8F8EohJ34M336M5PSpMqBf/sHkA/wrmiARWIedQFq4x+cRHh4Yoro1QOhVJAz0 4+3lrtcLs0bml2+ECMiCDFUFbYF3/5z2AWQRqxL9SyMtoxTg9ohfggp9V15FqnUO3CeB/9 eg+SjCmXTSEsnXIlJxdbr0EnuPzJt9e5VYLx8pOFW61onTXzxu/DQuSWBQy198BTH1L/mc eHMyKCPUiKA9z67yQlfoJYEmLoOj9tfH5RLmNVpzJJQP++Jx0bH6em/rJK5K2w== Date: Tue, 17 May 2022 15:30:45 +0200 From: Miquel Raynal To: Alexander Aring Cc: Alexander Aring , Stefan Schmidt , linux-wpan - ML , "David S. Miller" , Jakub Kicinski , Paolo Abeni , Network Development , David Girault , Romuald Despres , Frederic Blain , Nicolas Schodet , Thomas Petazzoni Subject: Re: [PATCH wpan-next v2 09/11] net: mac802154: Introduce a synchronous API for MLME commands Message-ID: <20220517153045.73fda4ee@xps-13> In-Reply-To: References: <20220512143314.235604-1-miquel.raynal@bootlin.com> <20220512143314.235604-10-miquel.raynal@bootlin.com> Organization: Bootlin X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org aahringo@redhat.com wrote on Sun, 15 May 2022 19:03:53 -0400: > Hi, >=20 > On Sun, May 15, 2022 at 6:28 PM Alexander Aring wro= te: > > > > Hi, > > > > On Thu, May 12, 2022 at 10:34 AM Miquel Raynal > > wrote: =20 > > > > > > This is the slow path, we need to wait for each command to be process= ed > > > before continuing so let's introduce an helper which does the > > > transmission and blocks until it gets notified of its asynchronous > > > completion. This helper is going to be used when introducing scan > > > support. > > > > > > Signed-off-by: Miquel Raynal > > > --- > > > net/mac802154/ieee802154_i.h | 1 + > > > net/mac802154/tx.c | 25 +++++++++++++++++++++++++ > > > 2 files changed, 26 insertions(+) > > > > > > diff --git a/net/mac802154/ieee802154_i.h b/net/mac802154/ieee802154_= i.h > > > index a057827fc48a..f8b374810a11 100644 > > > --- a/net/mac802154/ieee802154_i.h > > > +++ b/net/mac802154/ieee802154_i.h > > > @@ -125,6 +125,7 @@ extern struct ieee802154_mlme_ops mac802154_mlme_= wpan; > > > void ieee802154_rx(struct ieee802154_local *local, struct sk_buff *s= kb); > > > void ieee802154_xmit_sync_worker(struct work_struct *work); > > > int ieee802154_sync_and_hold_queue(struct ieee802154_local *local); > > > +int ieee802154_mlme_tx(struct ieee802154_local *local, struct sk_buf= f *skb); > > > netdev_tx_t > > > ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device= *dev); > > > netdev_tx_t > > > diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c > > > index 38f74b8b6740..ec8d872143ee 100644 > > > --- a/net/mac802154/tx.c > > > +++ b/net/mac802154/tx.c > > > @@ -128,6 +128,31 @@ int ieee802154_sync_and_hold_queue(struct ieee80= 2154_local *local) > > > return ieee802154_sync_queue(local); > > > } > > > > > > +int ieee802154_mlme_tx(struct ieee802154_local *local, struct sk_buf= f *skb) > > > +{ > > > + int ret; > > > + > > > + /* Avoid possible calls to ->ndo_stop() when we asynchronousl= y perform > > > + * MLME transmissions. > > > + */ > > > + rtnl_lock(); =20 > > > > I think we should make an ASSERT_RTNL() here, the lock needs to be > > earlier than that over the whole MLME op. MLME can trigger more than =20 >=20 > not over the whole MLME_op, that's terrible to hold the rtnl lock so > long... so I think this is fine that some netdev call will interfere > with this transmission. > So forget about the ASSERT_RTNL() here, it's fine (I hope). >=20 > > one message, the whole sync_hold/release queue should be earlier than > > that... in my opinion is it not right to allow other messages so far > > an MLME op is going on? I am not sure what the standard says to this, > > but I think it should be stopped the whole time? All those sequence =20 >=20 > Whereas the stop of the netdev queue makes sense for the whole mlme-op > (in my opinion). I might still implement an MLME pre/post helper and do the queue hold/release calls there, while only taking the rtnl from the _tx. And I might create an mlme_tx_one() which does the pre/post calls as well. Would something like this fit? Thanks, Miqu=C3=A8l